The invention relates to a sterilization installation for infusion solutions or the like which are filled in containers, in which installation the containers with the goods to be sterilized are exposed on shelves to a circulating, heated gaseous working medium and are subsequently cooled again by a circulating, indirectly cooled gaseous working medium. Sterilization installations of this type are described, for example, in the periodical "Die pharmazeutische industrie", 1975 (The pharmaceutical Industry); Heft (Vol.) 10, pages 825-829, Heft (Vol.) 11, pages 909-912, and Heft (Vol.) 12, pages 1071-1075. As working medium in such types of installations, one customarily uses either saturated steam, in given cases mixed with air, or circulating air is heated in the installation itself. When steam is used, and in particular during the cooling processes, a sudden pressure drop as a result of the condensation of the steam, and the danger of explosion of the hot containers associated therewith, have to be prevented through a correspondingly large supply of compressed air or of another gaseous protective medium. An improved apparatus of this type is described in a copending application by applicant, Ser. No. 890,202, filed on Apr. 20, 1978, having the same title, and assigned to the assignee of the present invention.
The increasing need for sterile infusion solutions or the like requires as economical an operation of the sterilization installations as possible. In cases of the known sterilization installations of the type here under discussion, the economics of operation are adversely affected thereby, namely in that the heating of the goods to be sterilized, the heat treatment at sterilization temperature, and the cooling of the goods to be sterilized after the heat treatment are all undertaken successively in a closed-off housing, which, together with its components, has to be heated and cooled again in each case.
A further problem, which has to be solved during the further development of the sterilization installations of the type here under discussion, is due to the demands made of the working conditions during the sterilization being more and more intensified, this being done in particular in view of the development of new highly sensitive infusion solutions or the like, and among other things, due to the need that the time between the preparation- and filling-operations of the solution to be sterilized, and the sterilization-process itself be shortened as much as possible. In the case of the known continuously operating sterilization installations, into which the containers filled with the sterilization goods can be introduced at once after the filling operations, a risk of a contamination of the solution exists, due to the use of a direct heat-exchange with heated or cooled water of the containers with the sterilization goods, for reasons which do not have to be explained here in detail; for this reason, the aforesaid demands can be met in cases of sterilization installations constructed for batch loading, the time intervals between the individual loading process being shortened.